Ricki,
Just want to add an extra hug and support you in your decision. What's right for you - is simply right for you and that's it. No explanation necessary, to anyone (and your Grandmother would most definitely understand) the only problem with decisions like this is the inevitable guilt, which can also play such havoc on the clarity of the situation.
I went through the same dilemma when I lost my Mum, everyone said "you MUST see her to say a final goodbye, pay your last respects etc" and against my better judgement, I did and I cannot even tell you how many years it has taken me to see beyond the last time I saw her and I wished I had not seen her that way, even though she looked so peaceful and her skin was flawless.
It breaks my heart even now and yet she would totally have understood.
Can't help any further with anything useful, but can say you know what's best in your heart and that is good enough.
*hugs*